1. Field of the Invention
The invention relates to a development processing device that supplies a liquid developer onto a glass substrate for photomask such as a reticle.
2. Description of the Background Art
For example, a photolithography step in a manufacturing process of a semiconductor device or a substrate such as a reticle is generally executed by performing processing such as resist application processing of forming a resist film by applying a resist liquid onto the substrate, exposure processing of performing exposure on the resist film on the substrate to form a predetermined pattern, and development processing of developing the resist film on the substrate by supplying a liquid developer onto the exposed substrate.
In this kind of conventional development processing device, a nozzle head discharges and aspirates a liquid developer, and therefore may cause a so-called air-biting phenomenon in which an ambient air is mixed into the liquid developer. A device for preventing this phenomenon is already known. This device includes an outer peripheral plate such as an approach stage that is rotatable together with a rotatable rotary base, and surrounds an outer periphery of a substrate held by a substrate holding member. This approach stage is employed for forming a liquid film that extends continuously over the surface of the substrate and its surface flush with the surface of the substrate.
In view of transfer of the substrate, a space is formed between the substrate and the outer peripheral plate. Therefore, a liquid may flow out through the space when the liquid film is being formed on the surfaces of the substrate and the approach stage. For preventing this problem, a development processing device disclosed in Japanese Patent Laying-Open No. 2005-236189 has a substrate holding member holding, by suction, the substrate in such a state that the substrate holding member is in intimate contact with a rear surface of an outer peripheral portion of the substrate throughout the circumference of the outer peripheral portion of the substrate. The substrate holding member is further configured such that a part of the substrate holding member opens to a space between it and the outer side surface of the substrate, and thereby forms a groove in which the liquid is kept.
In this kind of conventional development processing device, however, the rear surface of the substrate is always in contact with the substrate holding member during the processing so that it is impossible to wash contact portions of the rear substrate surface and the substrate holding member. Also, a part of the substrate holding member surrounds the substrate for holding the liquid film so that residues of the liquid developer may remain on that portion, and may contaminate the substrate. Since a suction line must be attached to a rotary unit, it is difficult to arrange the suction line inside the rotary base and the substrate holding member and to provide a sealing structure between the rotary and unrotary units. Since a seal member for such sealing is generally formed of, e.g., an O-ring, a complicated seal adjustment is required for applying a uniform pressure to the O-ring, and further the O-ring must be periodically replaced. Further, the rotary base and the substrate holding member are simultaneously rotated. Therefore, the rotary unit has a large weight and requires a motor of a large power. Also, a mechanism is required for removing heat generated by friction of the O-ring.